***LIMITED ITEM PLS ALLOW 4 BUSINESS DAYS HANDLING TO SHIP*** Piston set moly coated 3-7/16 inch bore and is .050 oversize. The compression ratio is 8.5:1. Set features cast construction with moly coating which helps reduce friction and wear. Wrist pins and lock pins included. **Note: Run engine at moderate speeds for at least 500 miles avoiding excessive running in lower gears in order to properly break-in new pistons and rings. FITS HARLEY: 1941-1977 FL, 1971-1977 FX,